Keyboard action assemblies



June 2, 1964 T. 5. L0 DUCA KEYBOARD ACTION ASSEMBLIES Filed NOV. 27, 1961 i l u Z9 mg g a g M? a 9 2 O INVENTOR. 7/ /0014: 5. 400m ATTORNEY United States Patent A O 3 135,153 KEYBOARD AcTIoN ASSEMBLIES Thomas S. Lo Duca, 2224 N. 24th Place, Milwaukee 5, Wis. Filed Nov. 27, 1961, Ser. No. 155,021 2 Claims. (Cl. 84433) This invention relates to improvements in keyboard action assemblies, and more particularly to a novel keyboard action assembly of the type adapted for installation in a organ, chord organ or similar musical instrument.

An object of the invention is to provide a device of the type characterized by ease of action.

Another object of the invention is to provide a keyboard action operable quietly and with a minimum amount of friction or wear.

Other and further objects of the invention will appear as the description proceeds, reference being had to the accompanying drawing, in which:

FIG. 1 is a fragmentary plan view of a keyboard assembly embodying the invention.

FIG. 2 is a fragmentary inverted plan view of the keyboard assembly with parts in section.

FIG. 3 is a side view partly in elevation and partly in section of the same.

Referring more particularly to the drawing, the numeral represents the device generally, comprising a chassis 11 formed of sheet material. Chassis 11 is of inverted channel-shaped formation comprising front and rear flanges 12 and 9 respectively, connected by a web 8. Front flange 12 is formed with a plurality of spaced vertical slots 13. Web 8 is formed with a raised ridge 14 which extends longitudinally of the chassis 11 in the region of the rear flange 9. In the embodiment illustrated, the web 8 extends rearwardly of the rear flange 9 and ridge 14 is formed in that portion thereof which overlies the rear flange. The raised ridge 14 may be of arcuate configuration and is formed with a plurality of parallel transverse slots 15 each of which is preferably in alignment with a slot 13 of the front Wall. Those portions of the ridges between the slots 15 have downwardly struck loops or eyes 17 which are in axial alignment and which receive therein a pivot rod 16 which extends transversely of the slots 15 along the undersurface of the ridge 14.

Each key 20 is of plastic in substantially channel form and has a longitudinal internal channel form 21 on its under side 22 adhesively secured thereto which retains a key mounting metal bar 23, each of the latter provided with an angular stop bar 24 depending from the frontal portion 25 of bar 23, and a central depending finger 26; Enlarged lobal portions 27 and 28 extend downwardly of each bar 23 in the region of the rear end thereof. Each pair of such lobal portions 27 and 28 are slightly spaced apart to provide a downwardly facing slot 28a therebetween which freely receives therein the pivot rod 16 and the eye 29 receives an end of coil spring 30 which is secured by its opposite end to the anchor element 31 on the web 8 rearwardly of the ridge 14.

The frontal vertical portion 12 of the chassis 11 has secured thereto by threaded means 32 the transverse angle member 33 which carries a coextensive pad element 34 to limit downward movement of the stop bar 24 which is limited in upward movement by. pad element 35. Pads 34 and 35 extend longitudinally of the chassis 11 across each slot 13 so as to provide cushioned limit stops for feet 24a of all of the stop bars 24.

From the foregoing, it is apparent that each key 20 can be readily removed from the chassis 11 individually by simply disconnecting one end of its spring 30 and then 3,135,153 Patented June 2, 1964 raising the rear end of bar 34 until the lobal members 27 and 28 are clear of the pivot rod 16 and its slot 15. Thereafter, a slight forward movement will withdraw the horizontal foot 24a of stop bar 24 from its slot 13 and the key 20 is entirely free of the chassis 11. Replacement of the key 20 or a new and undamaged key is readily accomplished by a reversal of the foregoing procedure. Slots 15 and 13 prevent lateral play of the keys 20 in use while the slots 28a and feet 24a of the stop bars 24 effectively prevent any substantial fore and aft movement of the keys 20 relative to the chassis 11. By providing members 27, 28 of lobe shape, the mouth of the slot 28a is funnel-shaped so that the rear ends of the bars 23 are readily guided into the correct engagement With the pivot rod 16 when a key 20 is being replaced. This speeds up the work but still insures a perfect alignment at each operation. Also, it protects the parts from damage during the application or removal of the keys 20.

It will be understood that the device is capable of many modifications in structure and design, without departing from the spirit of the invention, within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent of the United States, is:

1. A device of the class described comprising a chassis of inverted channel form including front and rear flanges and a web connecting said flanges and extending from said front flange to at least said rear flange, said web being formed with a raised ridge extending longitudinally of said web in the region of said rear flange, said ridge being formed with a series of transversely extending spaced and parallel slots therethrough, said ridge between said slots being formed with a plurality of downwardly struck loops, said loops being axially aligned, a pivot rod seated in said loops and extending the length of said ridge across said slots, a plurality of key bars, each key bar having front and rear ends, a key carried by each front end, each rear end being formed with a pair of depending lobal portions in slightly spaced relation to provide a downwardly opening slot therebetween, each pair of lobal portions providing a funnel-shaped opening for its slot, said lobal portions of said key bars extending at least partially through separate slots in said ridge whereby said funnel shaped mouths of said slots guide said pivot rod into said slots to provide a single pivotal mount for all of said key bars, a spring for retaining each key bar on said pivot rod, means connecting each spring to its key bar rearwardly of said lobal portions, means connecting each spring to said chassis rearwardly of said ridge, and at least one of said connections for said spring being a readily detachable connection.

2. The combination of claim 1, wherein said front flange of said chassis is formed with a series of vertically disposed slots therethrough, each of said vertical slots being aligned with a slot in said ridge, and each key bar including depending angular stop bar having a laterally extending portion freely received in one of said vertical slots.

References Cited in the file of this patent UNITED STATES PATENTS 1,061,986 Ahern et a1. Dec. 2, 1953 2,826,953 Scherer Mar. 18, 1958 2,852,973 Corbett Sept. 23, 1958 3,002,413 Scherer Oct. 3, 1961 FOREIGN PATENTS 1,061,986 France Dec. 2, 1953 

1. A DEVICE OF THE CLASS DESCRIBED COMPRISING A CHASSIS OF INVERTED CHANNEL FORM INCLUDING FRONT AND REAR FLANGES AND A WEB CONNECTING SAID FLANGES AND EXTENDING FROM SAID FRONT FLANGE TO AT LEAST SAID REAR FLANGE, SAID WEB BEING FORMED WITH A RAISED RIDGE EXTENDING LONGITUDINALLY OF SAID WEB IN THE REGION OF SAID REAR FLANGE, SAID RIDGE BEING FORMED WITH A SERIES OF TRANSVERSELY EXTENDING SPACED AND PARALLEL SLOTS THERETHROUGH, SAID RIDGE BETWEEN SAID SLOTS BEING FORMED WITH A PLURALITY OF DOWNWARDLY STRUCK LOOPS, SAID LOOPS BEING AXIALLY ALIGNED, A PIVOT ROD SEATED IN SAID LOOPS AND EXTENDING THE LENGTH OF SAID RIDGE ACROSS SAID SLOTS, A PLURALITY OF KEY BARS, EACH KEY BAR HAVING FRONT AND REAR ENDS, A KEY CARRIED BY EACH FRONT END, EACH REAR END BEING FORMED WITH A PAIR OF DEPENDING LOBAL PORTIONS IN SLIGHTLY SPACED RELATION TO PROVIDE A DOWNWARDLY OPENING SLOT THEREBETWEEN, EACH PAIR OF LOBAL PORTIONS PROVIDING A FUNNEL-SHAPED OPENING FOR ITS SLOT, SAID LOBAL PORTIONS OF SAID KEY BARS EXTENDING AT LEAST PARTIALLY THROUGH SEPARATE SLOTS IN SAID RIDGE WHEREBY SAID FUNNEL SHAPED MOUTHS OF SAID SLOTS GUIDE SAID PIVOT ROD INTO SAID SLOTS TO PROVIDE A SINGLE PIVOTAL MOUNT FOR ALL OF SAID KEY BARS, A SPRING FOR RETAINING EACH KEY BAR ON SAID PIVOT ROD, MEANS CONNECTING EACH SPRING TO ITS KEY BAR REARWARDLY OF SAID LOBAL PORTIONS, MEANS CONNECTING EACH SPRING TO SAID CHASSIS REARWARDLY OF SAID RIDGE, AND AT LEAST ONE OF SAID CONNECTIONS FOR SAID SPRING BEING A READILY DETACHABLE CONNECTION. 